21622236 has 12 divisors (see below), whose sum is σ = 50451912. Its totient is φ = 7207408.

The previous prime is 21622219. The next prime is 21622241. The reversal of 21622236 is 63222612.

It is a tau number, because it is divible by the number of its divisors (12).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 900915 + ... + 900938.

It is an arithmetic number, because the mean of its divisors is an integer number (4204326).

Almost surely, 2^21622236 is an apocalyptic number.

It is an amenable number.

21622236 is an abundant number, since it is smaller than the sum of its proper divisors (28829676).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21622236 is a wasteful number, since it uses less digits than its factorization.

21622236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1801860 (or 1801858 counting only the distinct ones).

The product of its digits is 1728, while the sum is 24.

The square root of 21622236 is about 4649.9716128166. The cubic root of 21622236 is about 278.5908623993.

Adding to 21622236 its reverse (63222612), we get a palindrome (84844848).

The spelling of 21622236 in words is "twenty-one million, six hundred twenty-two thousand, two hundred thirty-six".